三种钢基疏水表面微观形貌的分形特征及其对润湿性的影响

Fractal Characteristics of the Microstructures of Three Hydrophobic Surfaces with Steel Substrate and Their Effects on Wettability

采用化学刻蚀与低表面能物质修饰相结合的方法,通过调控刻蚀时间在304不锈钢、X80管线钢和45#钢表面构造不同的微观形貌;借助扫描电子显微镜采集不同材料表面的微观形貌,并采用接触角测量仪测量其润湿性能;应用Matlab软件编程计算分形参数.结果表明,3种材料构造的疏水表面均具有分形特征,且最佳刻蚀时间为30 min,此时多重分形谱子集维数最大值最靠左,对应的奇异性指数最小,表征表面微观形貌的分形维数也达到最大值;分形维数与接触角线性拟合效果优良,接触角随分形维数的增大而增大.

The microstructures on 304 stainless steel,X80 pipeline steel and 45# steel surfaces were prepared at different etching times by using the chemical etching and modification with low-surface-energy material.The microstructures and wettabilities of different material surfaces were obtained by a scanning electronic microscope and a contact angle meter,respectively.The fractal parameters were calculated by Matlab software.The results showed that the hydrophobic surfaces prepared on three materials had fractal characteristics.The optimal etching time was 30 min.At that time,the maximum subset of multifractal spectrum was close to the leftmost,the corresponding singularity index was the smallest,and the fractal dimension also reached the maximum.The linear fitting results of fractal dimension and contact angle was good.The contact angle increased with the increase of fractal dimension.